A parliamentary system is a system of democraticgovernance of a state where the executive derives its democratic legitimacy from its ability to command the confidence of the legislature, typically a parliament, and is also held accountable to that parliament. In a parliamentary system, the head of state is usually a person distinct from the head of government. This is in contrast to a presidential system, where the head of state often is also the head of government and, most importantly, the executive does not derive its democratic legitimacy from the legislature.

Countries with parliamentary democracies may be constitutional monarchies, where a monarch is the head of state while the head of government is almost always a member of parliament (such as the United Kingdom, Denmark, Sweden and Japan), or parliamentary republics, where a mostly ceremonial president is the head of state while the head of government is regularly from the legislature (such as Ireland, Germany, India and Italy). In a few parliamentary republics, such as Botswana, South Africa, and Suriname, among some others, the head of government is also head of state, but is elected by and is answerable to parliament. In bicameral parliaments, the head of government is generally, though not always, a member of the lower house.

Parliamentarianism is the dominant form of government in Europe, with 32 of its 50 sovereign states being parliamentarian. It is also common in the Caribbean, being the form of government of 10 of its 13 island states, and in Oceania. Elsewhere in the world, parliamentary countries are less common, but they are distributed through all continents, most often in former colonies of the British Empire.

Since ancient times, when societies were tribal, there were councils or a headman whose decisions were assessed by village elders. Eventually, these councils have slowly evolved into the modern parliamentary system.

In the Kingdom of Great Britain, the monarch, in theory, chaired cabinet and chose ministers. In practice, King George I's inability to speak English led the responsibility for chairing cabinet to go to the leading minister, literally the prime or first minister, Robert Walpole. The gradual democratisation of parliament with the broadening of the voting franchise increased parliament's role in controlling government, and in deciding who the king could ask to form a government. By the nineteenth-century, the Great Reform Act of 1832 led to parliamentary dominance, with its choice invariably deciding who was prime minister and the complexion of the government.[8][9]

Other countries gradually adopted what came to be called the Westminster Model of government, with an executive answerable to parliament, but exercising powers nominally vested in the head of state, in the name of the head of state. Hence the use of phrases like Her Majesty's government or His Excellency's government. Such a system became particularly prevalent in older British dominions, many of whom had their constitutions enacted by the British parliament; examples include Australia, New Zealand, Canada, the Irish Free State and the Union of South Africa. Some of these parliaments evolved were reformed from, or were initially developed as distinct from their original British model: the Australian Senate, for instance, has since its inception more closely reflected the US Senate than the British House of Lords; whereas since 1950 there is no upper house in New Zealand.

Democracy and parliamentarianism became increasingly prevalent in Europe in the years after World War I, partially imposed by the democratic victors, Great Britain and France, on the defeated countries and their successors, notably Germany's Weimar Republic and the new Austrian Republic. Nineteenth-century urbanisation, the Industrial Revolution and, modernism had already fuelled the political left's struggle for democracy and parliamentarianism for a long time. In the radicalised times at the end of World War I, democratic reforms were often seen as a means to counter popular revolutionary currents.

A parliamentary system may be either bicameral, with two chambers of parliament (or houses) or unicameral, with just one parliamentary chamber. In the case of a bicameral parliament, this is usually characterised by an elected lower house that has the power to determine the executive government and an upper house which may be appointed or elected through a different mechanism from the lower house.

Scholars of democracy such as Arend Lijphart distinguish two types of parliamentary democracies: the Westminster and Consensus systems.[10]

The Western European parliamentary model (e.g. Spain, Germany) tends to have a more consensual debating system and usually has semi-circular debating chambers. Consensus systems have more of a tendency to use proportional representation with open party lists than the Westminster Model legislatures. The committees of these Parliaments tend to be more important than the plenary chamber. Some West European countries' parliaments (e.g. in the Netherlands, Luxembourg and Sweden) implement the principle of dualism as a form of separation of powers. In countries using this system, Members of Parliament have to resign their place in Parliament upon being appointed (or elected) minister. Ministers in those countries usually actively participate in parliamentary debates, but, are not entitled to vote.

Implementations of the parliamentary system can also differ on the manner of how the prime minister and government are appointed and as to whether the government needs the explicit approval of the parliament, rather than just the absence of its disapproval. Some countries such as India also require the prime minister to be a member of the legislature, though in other countries this only exists as a convention.

The head of state appoints a prime minister who will likely have majority support in parliament. While in practice most prime ministers under the Westminster system (including Australia, Canada, India, New Zealand and the United Kingdom) are the leaders of the largest party in parliament, technically the appointment of the prime minister is a prerogative exercised by the monarch, the governor-general, or the president. No parliamentary vote takes place on who is forming a government, but since parliament can immediately defeat the government with a motion of no confidence, the head of state is limited by convention to choosing a candidate who can command the confidence of parliament, and thus has little or no influence in the decision.[citation needed]

The head of state appoints a prime minister who must gain a vote of confidence within a set time. Examples: Italy, Thailand.

The head of state appoints the leader of the political party holding a plurality of seats in parliament as prime minister. For example, in Greece, if no party has a majority, the leader of the party with a plurality of seats is given an exploratory mandate to receive the confidence of the parliament within three days. If this is not possible, then the leader of the party with the second highest seat number is given the exploratory mandate. If this fails, then the leader of the third largest party is given it and so on.

The head of state nominates a candidate for prime minister who is then submitted to parliament for approval before appointment. Example: Spain, where the King sends a nomination to parliament for approval. Also, Germany where under the German Basic Law (constitution) the Bundestag votes on a candidate nominated by the federal president. In these cases, parliament can choose another candidate who then would be appointed by the head of state.

Parliament nominates a candidate whom the head of state is constitutionally obliged to appoint as prime minister. Example: Japan, where the Emperor appoints the Prime Minister on the nomination of the Diet. Also, Ireland where the President of Ireland appoints the Taoiseach on the nomination of the Dáil.

A public officeholder (other than the head of state or their representative) nominates a candidate, who, if approved by parliament, is appointed as prime minister. Example: Under the Swedish Instrument of Government (1974), the power to appoint someone to form a government has been moved from the monarch to the Speaker of Parliament and the parliament itself. The speaker nominates a candidate, who is then elected to prime minister (statsminister) by the parliament if an absolute majority of the members of parliament does not vote no (i.e. he can be elected even if more members of parliament vote No than Yes).

Direct election by popular vote. Example: Israel, 1996–2001, where the prime minister was elected in a general election, with no regard to political affiliation, and whose procedure can also be described as of a semi-parliamentary system.[14][15]

Furthermore, there are variations as to what conditions exist (if any) for the government to have the right to dissolve the parliament:

In some countries, such as Denmark, Malaysia, Australia and New Zealand, the prime minister has the de facto power to call an election, at will. This was also the case in the United Kingdom until the passage of the Fixed-term Parliaments Act 2011.

In Israel, parliament may vote in order to call an election or pass a vote of no confidence against the government.

Other countries only permit an election to be called in the event of a vote of no confidence against the government, a supermajority vote in favour of an early election or prolonged deadlock in parliament. These requirements can still be circumvented. For example, in Germany in 2005, Gerhard Schröder deliberately allowed his government to lose a confidence motion, in order to call an early election.

In Sweden, the government may call a snap election at will, but the newly elected Riksdag is only elected to fill out the previous Riksdag's term. The last time this option was used was in 1958.

Norway is unique among parliamentary systems in that the Storting always serves the whole of its four-year term.

The parliamentary system can be contrasted with a presidential system which operates under a stricter separation of powers, whereby the executive does not form part of—nor is appointed by—the parliamentary or legislative body. In such a system, parliaments or congresses do not select or dismiss heads of governments, and governments cannot request an early dissolution as may be the case for parliaments. There also exists the semi-presidential system that draws on both presidential systems and parliamentary systems by combining a powerful president with an executive responsible to parliament, for example, the French Fifth Republic.

Parliamentarianism may also apply to regional and local governments. An example is the city of Oslo, which has an executive council (Byråd) as a part of the parliamentary system.

A few parliamentary democratic nations such as India,[16] Pakistan, and Bangladesh, have enacted an anti-defection law, which prohibits a member of the legislature from switching to another party after being elected. With this law, elected representatives lose their seats in parliament if they vote contrary to the directions of their party.

One of the commonly attributed advantages to parliamentary systems is that it is faster and easier to pass legislation,[17] as the executive branch is formed by the direct or indirect support of the legislative branch and often includes members of the legislature. Thus the executive (as the majority party or coalition of parties in the legislature) has a majority of the votes and can pass legislation at will. In a presidential system, the executive is often chosen independently from the legislature. If the executive and the majority of the legislature are from different political parties, then stalemate can occur. Thus the executive might not be able to implement its legislative proposals. An executive in any system (be it parliamentary, presidential or semi-presidential) is chiefly voted into office on the basis of his or her party's platform/manifesto,[citation needed] and the same is also true of the legislature.

In addition to quicker legislative action, a parliamentary government has attractive features for nations that are ethnically, racially, or ideologically divided. In a presidential system, all executive power is vested in one person: the president. In a parliamentary system, with a collegial executive, power is more divided. In the 1989 Lebanese Taif Agreement, in order to give Muslims greater political power, Lebanon moved from a semi-presidential system with a strong president[dubious – discuss] to a system more structurally similar to classical parliamentary government. Iraq similarly disdained a presidential system out of fears that such a system would be tantamount to Shiite domination; Afghanistan's minorities refused to go along with a presidency as strong as the Pashtuns desired.

It can also be argued that power is more evenly spread out in parliamentary government, as the government and prime minister do not have the ability to make unilateral decisions as the entire government cabinet is answerable and accountable to parliament. Parliamentary systems are less likely to allow celebrity-based politics to fully dominate a society unlike what often happens in presidential systems, where name-recall and popularity can catapult a celebrity, actor, or popular politician to the presidency despite such candidate's lack of competence and experience.

In his 1867 book The English Constitution, Walter Bagehot praised parliamentary governments for producing serious debates, for allowing for a change in power without an election, and for allowing elections at any time. Bagehot considered the four-year election rule of the United States to be unnatural, as it can potentially allow a president who has disappointed the public with a dismal performance in the second year of his term to continue on until the end of his 4-year term. Under a parliamentary system, a prime minister that has lost support in the middle of his term can be easily replaced by his own peers.

Some scholars like Juan Linz, Fred Riggs, Bruce Ackerman, and Robert Dahl have found that parliamentary government is less prone to authoritarian collapse. These scholars point out that since World War II, two-thirds of Third World countries establishing parliamentary governments successfully made the transition to democracy. By contrast, no Third World presidential system successfully made the transition to democracy without experiencing coups and other constitutional breakdowns.

A recent World Bank study found that parliamentary systems are associated with less corruption.[18] This study's findings are supported by a separate study that arrived at the same conclusions.[19]

Some constituencies may have a popular local candidate under an unpopular leader (or the reverse), forcing a difficult choice on the electorate. Mixed-member proportional representation (where voters cast two votes) can make this choice easier by allowing voters to cast one vote for the local candidate at the constituency level but also cast a second vote for another party at the wider parliamentary level.

Although Bagehot praised parliamentary governments for allowing an election to take place at any time, the lack of a definite election calendar can be abused. Previously under some systems, such as the British, a ruling party could schedule elections when it felt that it was likely to retain power, and so avoid elections at times of unpopularity. (Election timing in the UK, however, is now partly fixed under the Fixed-term Parliaments Act 2011.) Thus, by a wise timing of elections, in a parliamentary system, a party can extend its rule for longer than is feasible in a functioning presidential system. This problem can be alleviated somewhat by setting fixed dates for parliamentary elections, as is the case in several of Australia's state parliaments. In other systems, such as the Dutch and the Belgian, the ruling party or coalition has some flexibility in determining the election date. Conversely, flexibility in the timing of parliamentary elections can avoid periods of legislative gridlock that can occur in a fixed period presidential system. Such feature in being able to time elections whenever it is advantageous to the ruling party is not a real issue, however, as voters ultimately have the ability to still make the choice of whether to vote for the ruling party or not.

Maronite Christian president is elected by the Parliament of Lebanon. He appoints the Prime Minister (a Sunni Muslim) and the cabinet. The Parliament thereafter approves the Cabinet of Lebanon through a vote of confidence (a simple majority).

In theory, chancellor and ministers are appointed by the President. As a practical matter, they are unable to govern without the support (or at least toleration) of a majority in the National Council. The cabinet is politically answerable to the National Council and can be dismissed by the National Council through a motion of no confidence.

The Monarch appoints, based on recommendations from the leaders of the parties in Folketinget, the cabinet leader who is most likely to successfully assemble a Cabinet which will not be disapproved by a majority in Folketinget.

Estonia

Riigikogu elects the Prime Minister candidate nominated by the President of the Republic (normally this candidate is the leader of the parliamentary coalition of parties). The Government of the Republic of Estonia is later appointed by the President of the Republic under proposal of the approved Prime Minister candidate. The Riigikogu may remove the Prime Minister and any other member of the government through a motion of no confidence.

^"Constitutionalism: America & Beyond". Bureau of International Information Programs (IIP), U.S. Department of State. Archived from the original on 24 October 2014. Retrieved 30 October 2014. The earliest, and perhaps greatest, victory for liberalism was achieved in England. The rising commercial class that had supported the Tudor monarchy in the 16th century led the revolutionary battle in the 17th, and succeeded in establishing the supremacy of Parliament and, eventually, of the House of Commons. What emerged as the distinctive feature of modern constitutionalism was not the insistence on the idea that the king is subject to law (although this concept is an essential attribute of all constitutionalism). This notion was already well established in the Middle Ages. What was distinctive was the establishment of effective means of political control whereby the rule of law might be enforced. Modern constitutionalism was born with the political requirement that representative government depended upon the consent of citizen subjects.... However, as can be seen through provisions in the 1689 Bill of Rights, the English Revolution was fought not just to protect the rights of property (in the narrow sense) but to establish those liberties which liberals believed essential to human dignity and moral worth. The "rights of man" enumerated in the English Bill of Rights gradually were proclaimed beyond the boundaries of England, notably in the American Declaration of Independence of 1776 and in the French Declaration of the Rights of Man in 1789.

^Dr Andrew Blick and Professor George Jones — No 10 guest historian series, Prime Ministers and No. 10 (1 January 2012). "The Institution of Prime Minister". Government of the United Kingdom: History of Government Blog. Retrieved 15 April 2016.